Baseboard heat exchanger apparatus



1963 A. J. FOWELL 3,395,752

BASEBOARD HEAT EXCHANGER APPARATUS Filed June 10. 1966 INVENTOR. AndrewJ. Fowell AT'T ORNEY United States Patent 3,395,752 BASEBOARD HEATEXCHANGER APPARATUS Andrew J. Fowell, South Bound Brook, N.J., assignorto American Standard Inc., a corporation of Delaware Filed June 10,1966, Ser. No. 556,678 4 Claims. (Cl. 16555) ABSTRACT OF THE DISCLOSUREThis invention relates to a forced air baseboard heat exchanger unit.The unit includes a crossflow fan, a housing having a scroll adjacent tothe fan, and a heat exchanger mounted above the fan and within thehousing. The fan is made of a hollow cylindrical member formed ofexpanded sheet metal and is retained between flat end plates to whichshaft means are connected so that the member may be rotated. The fan ispositioned near the bottom of the housing which has an opening extendingsubstantially across the length of the housing and over the entire axialextent of the rotor. The heat exchanger extends along at least a portionof the length of the housing.

This invention relates to a forced air baseboard unit utilizing acrossfiow fan for both the heating and cooling operations, and to thestructure of the crossflow fan that is utilized and specially adaptedfor use in such baseboard unit.

Hydronic air-heating baseboard units, consisting of finned tubing, areat present limited to heating applications, because they rely onconvection for the removal of heat from the unit. The heat distributionthroughout the room is similarly achieved through convection. Such heatis derived from heated water transferred through the tubing, which thenconducts the heat to the fins from which the heat is transferred to theair by the convection movement.

If cold water is passed through the tubing of such a unit, a layerofcold air is formed across the floor of the room. If a suitable fanwere available to circulate the air from the floor over the finned unitof the baseboard and then to discharge the air into the higher parts ofthe room, such a hydronic baseboard type unit could be used for coolingapplications during the summer as well as for heating in the winter.

One object of this invention is to provide a suitable fan of specialdesign and construction to circulate air from the lower level onto andover the finned unit of such a baseboard unit and to discharge the airto the higher parts of a room.

Another object of the invention is to provide a baseboard style unitwhich can be utilized for cooling applications as well as for heatingapplications, and which includes a crossfiow fan specially adapted foruse in such a unit.

One of the main advantages of a crossflow fan, compared with a standardcentrifugal fan, is that its total air delivery is approximatelyproportional to the length of the rotor, as a result of the tangentialrather than axial air inlet. Such a crossflow fan is frequently usedwhen a long narrow air supply is required or particularly advantageous.

A long crossflow rotor with blade supported parallel to the rotor axis,suffers from a number of structural weaknesses. Firstly, centrifugalloads or forces cause the blades to bend outwards and to touch thecasing, or to cause unbalance. Secondly, such a bladed construction ofthe rotor has very low torsional stiffness, and therefore, lackstorsional stability or rigidity. Furthermore, expensive dies arerequired to make the bladed rotors, as a re- 3,395,752 Patented Aug. 6,1968 salt of which, they are costly to produce. Further, straight axialblades also produce an undesirable edge tone when passing the cut-offedge of an outlet port for the air stream being moved.

An object of this aspect of the invention is to provide a crossfiow fanrotor that shall avoid the foregoing disadvantages and yet be economicalto manufacture.

Another object is to provide a crossflow fan rotor which while beinginexpensively constructed has substantial torsional rigidity.

Another object of the invention is to provide a crossflow fan rotorhaving a peripheral structure which will provide a relatively stable andtorsionally rigid element, with natural symmetry, and with relativelyuniform axial mass, that will permit a number of such rotors to beconnected together end-to-end and driven from one end, whenappropriately supported axially.

Initially, the invention contemplates a rotor for a crossflow fancomprising a hollow cylindrical member formed from a sheet of expandedmetal. End plates are connected to the peripheral edges of the member. Ashaft means is connected to each of the end plates for rotating themember about its cylindrical axis.

Further, the rotor can be incorporated into a crossflow fan by disposinga scroll about the rotor. The scroll extends substantially across theentire axial extent of the rotor and only along a portion of itscircumferential extent.

Finally, the crossflow fan can be incorporated in a temperature controlunit by disposing the fan in a housing having an air inlet near itsbottom and an air outlet near its top. In the housing, above the fan,there is a heat exchanger so that air drawn in from the bottom of thehousing is forced by the fan across the heat exchanger to the outlet ofthe housing.

Other objects, the features and advantages of the invention are morefully described in the following specification, which may be consideredwith reference to the accompanying drawings, which show by way ofexample and not limitation, the now preferred embodiment of theinvention.

In the drawings:

FIGURE 1 is a transverse vertical sectional view of a forced-airtemperature control unit of the baseboard type with a crossflow fanaccording to the invention;

FIGURE 2 is a similar transverse vertical section, partially inelevation, of a modification of a crossflow fan forced-air baseboardunit of FIGURE 1;

FIGURE 3 is a side elevational view of the rotor of the crossflow fan ofFIGURES 1 and 2; and

FIGURE 4 is a transverse sectional view of the rotor of FIGURE 3 showingthe general disposition of the rotor relative to a schematic duct intowhich the rotor is to direct and drive the air stream.

As shown in FIGURE 1, the baseboard unit 10, for heating or cooling astream of air and then directing such heated or cooled air stream intoan adjoining space, such as a room or compartment is usually disposedagainst a wall. The elements of the baseboard unit 10 include a finnedheat exchanger 25 to serve as a heating and cooling unit, a rotor 30,disposed below the finned heat exchanger 25, a lower conduit-formingscroll 32 to define a horn opening space 34 for the air stream to bedriven, by the rotor 30, upwardly past the heat exchanger 25, and anupper region 35 which defines one end .of an outlet or discharge passage38. The size of passage 38 is defined by louvers 40, that are angularlyadjustable, in the passage 38, between the nose 36, of the upper region35 and an upper edge 42 of a front facing wall or sheet 45 that extendsalong the length of the baseboard unit. Sheet 45 serves as a front wallof the boxlike structure for enclos- 3 L ing the-operating length of thebaseboard unit 10. The lower end 'of' the front wall 45 is provided withan opening for an inlet 48 which includes a filter, that extendsdownward to a front sill or'base portion 50 at the lower front end ofthe lower scroll 32, adjacent the rotor 30'. The sill 50 and the bottomof the scroll 32 of which it forms a part are shown in the usualposition resting on the floor 52 of the room or compartment that is toreceive the heated or cooled air from the baseboard unit.

A condensate drain 54 is shown supported on the rear wall 20 at aposition where the drain 54 will receive any moisture that drips olf thefin structure of the heat-transfer element 25.

Heat transfer element 25, which may serve either as a heating or as acooling element, consists of a conduit or pipe 55, preferably of goodheat conducting material, such as copper or brass, to which a series ofparallel fins 57 of heat conducting material, also such as copper oraluminum, are mechanically joined, to provide a good heatconductingconnection. Fins 57 may be individual stampings, relatively square, asshown, or the fin structure may consist .of a continuous metallic strip,helically wound on the tubing 55 and joined to the pipe or tubing 55along the inner contacting edge of such helically wound material.

Where the fins 57 are substantially of square shape or of rectangularshape, the lower edges 58 are slightly inclined in order to provide apitch along which any moisture collecting on the fins, during coolingoperation, will flow to the corner 59 of the fins and then drop off intothe condensate drain or gutter 54, which in turn may then be suitablyconnected to drain off to a sewer drain (not shown).

The modification of the baseboard unit 10, as shown in FIGURE 2 isprimarily concerned with an alternate embodiment for condensate removal.A lower scroll 62 is provided with suitable openings or perforations 64at the bottom level so that the moisture that may condense on the fins57 will drip off the lowermost corner 59, drop into the curved lowerscroll 62 and run off at the lowermost point at the openings 64 into thecondensate drain 66 from which any accumulated moisture there collectedmay be drained off into a suitable conduit leading to a sewer drainpipe. The remaining elements of this baseboard unit are the same as theelements of the baseboard unit 10 of FIGURE 1.

The construction of the rotor 30 may now be considered. As shown inFIGURES 3 and 4, a sheet of expand metal mesh 70 is formed into acylinder, and its longitudinal side edges then appropriately secured asby welding or soldering, to hold the cylinder as a closed structure. Twoend plates 74 and 76 are secured at the outer edges of the cylinder 72to support and hold the cylinder 72 in symmetrical co-axial alignmentwith the two end plates 74 and 76, all of which constitute alightweight, relatively rigid and stable structure. The two end plates74 and 76 are provided with axial bosses 78 and 79 that may serve as endshafts for the cylindrical fan 30 thus formed, or those axial bosses 78and 79 may be utilized as connecting bosses or terminals to permit twoadjacent coaxial rotors to be mechanically coupled and driven by asingle driving motor connected to any one of the outer axial shafts suchas 78 or 79.

As indicated in FIGURES 3 and 4, the larger flat side edges or webs 80of the diamond shaped perforations formed in the expanded metal mesh 70, function as shallow radially extending ribs parallel to the axis ofrotation, and in most effective position to serve as vanes to move theair, along the entire peripheral part of engagement between those webs80, of the diamonds of the mesh, and the air directly engaged by thosewebs. As seen in FIG- URE 4, the webs 80 are aligned in a directionforward of radial. Consequently, the fans are operative to move the airin a path from an inlet region of first engagement with an incomingair-flow stream to the outlet region at the mouth of a substantiallyexponential-shaped horn, as defined in the space between the virtualperiphery 'of the rotor 30 and the surface of the lower scroll 32 ofFIG- URES l and 4, for example, or between the rotor and the lowerscroll 62 of the modification in FIGURE 2.

The operation of the entire combination may now be considered. j I I .l

The fluid conducting pipe 55 filled with'a'stream of water at elevatedtemperature for heating-purposes. The heat from the water in the pipe 55is then transmitted to the fins 57, and air drawn in through the inlet48 is driven upwardly by the rotor 30, along the scroll 32 and out ofopening 34, through the spaces between the heated fins 57, and thenupwards and through the passage 38, to the extent permitted by theposition of the discharge louvers 40. The cold air from the floor levelis thus heated in passage over the fins, and is then directed upwardinto the room or space according to the inclination of the dischargelouvers 40. i

In the case where cooling action is desired, cold water is fed throughpipe 55, and the air at floor level is drawn in through the inlet 48, asbefore, and directed and driven over the surfaces of the cold fins 57and then similarly up past the discharge louvers 40 and out of thepassage 38 into the space in the room or compartment.

Thus, either heating or cooling action may be achieved according to thetemperature of the heating or cooling medium, such as the hot or coldwater in the pipe 55, and the transfer of heat from the fins to the airor from the air to the fins, depending upon the nature and the directionof heat transfer for the air treatment.

By means of the construction shown, a quietly operating unit isachieved. In addition, an inexpensive and rigid rotor structure isobtained.

There will now be obvious to those skilled in the art many modificationsand variation which satisfy the objects of the invention withoutdeparting from the spirit and scope thereof as defined in the appendedclaims.

What is claimed is:

1. A baseboard type of heat exchanger comprising: a vertically oriented,baseboard housing; said housing having an air inlet near the bottomthereof and an air outlet near the top thereof; a heat exchangerextending along at least a portion of the length of said housing; saidheat exchanger com-prising a finned conduit; a scroll below said heatexchanger and having a length substantially equal to the length of theheat exchanger, said scroll having an outlet opposite said heatexchanger and an inlet opposite the air inlet of said housing; and acrossfiow rotor disposed within said scroll and extending substantiallyalong the length thereof, said rotor comprising a hollow cylindricalmember formed by a sheet of expanded metal and first and second flat endplates, each connected to one of the peripheral edges of said member;and shaft means connected to said end plates for rotating said memberabout the cylindrical axis thereof; said housing having means to collectcondensate from said finned conduit.

2. The baseboard type of heat exchanger of claim 1 wherein said heatexchanger comprises a horizontally extending fluid conduit and aplurality of platelike radiating fins vertically extending from saidconduit and further comprising a condensate collecting means disposedbelow said fins.

3. The baseboard type of heat exchanger of claim 1 wherein saidplatelike radiating fins include bottom portions oriented at angles tothe horizontal, and said condensate collecting means being disposed tocollectcondensate dripping from said bottom portion;

4. The baseboard type of heat exchanger of claim 1 wherein said sheet ofexpanded metal is provided with a two dimension array of perforations,each of said perforations having a length dimension greater. than thewidth dimension, said length dimensions being substantially parallel tothe axis of said member, and webs extending between said perforations,certain of said webs being radial.

References Cited UNITED STATES PATENTS Pierce 165-55 X Walker 165122 XHarder 230134 Schlumbohm 230252 Simmons 62-291 6 7/ 1960 Tyler 62-285 X9/ 1961 Mullin et a1 62291 X 8/1962 Allender 62-285 8/1965 Laing 230-125X FOREIGN PATENTS 4/ 1964 Great Britain. 9/ 1962 Great Britain.

10 ROBERT A. OLEARY, Primary Examiner.

A. W. DAVIS, Assistant Examiner.

